Garage door extension springs can be deadly if they do not have a safety cable. They are under extreme tension.
Springs counter balance your garage door. If you didn’t have springs, most doors, especially older wood doors, would be difficult or impossible to lift.
There are two types of springs. A torsion spring is mounted on the garage door overhead. Extension springs are connected to the door mounting hardware and then to the door with a cable and pulley.
The springs and cables are under very high stress when extended. If the spring or cable were to break they can cause damage, injury or death. This isn’t an exaggeration. If nothing else, a failed spring could cause severe damage to your car.
The video below will give you an idea of the forces involved. In this case, the cable was released. When the spring fails without a safety cable, you have a much heavier piece going in random directions. A cable failure MIGHT not be as bad as a spring failure.
The picture below is a spring that was installed perhaps 30 to 40 years ago, well before the requirements for safety cables.
These springs, when extended, are about 3 times longer than when they are not under tension. There is quite a bit of potential energy stored when the door is down.
One very expensive solution is to replace the doors. This can run about $3000 dollars and up per single door. I weighed a do-it-myself option and decided that it was a project that would be better to outsource.
The other solution is to install safety cables. You can do it yourself for about $20 per set of cables and an hour or two of time. You can also pay an installer about $150 to $250 to do the job. WARNING – working around springs and garage doors can be dangerous or deadly. The old wood doors I have are extremely heavy.
If you decide to do this job yourself – USE CAUTION. There is a serious risk of death or injury when working around the doors and springs. Do not underestimate it. A 40 year old wood door with multiple layers of paint that has soaked up moisture can be almost 300 pounds.
You need to work with the doors up so that ALL tension is off the springs and the door needs to be locked in place with something like vice grips on the rails.
The idea is to run the cable through the spring, anchoring it in to the frame. The cable needs to be pulled taught. My first attempt didn’t go very well in that respect. When I do the other door I plan on using a turnbuckle to get it taut. If it is loose it can bind in the pulley (and damage the door or opener) and it will cause binding.
Below is a spring with a cable threaded through. The cable is rubbing on the bolt head. That needs to be changed.
The cable kits are available at home stores and online for about 10 to 15 dollars a set.
Summary
Take a quick look at your garage doors. If you have extension springs, check for a safety cable. If it is missing or worn, install or replace it.
“I just started contacting garage repair companies and Precision Garage (national franchise or something) wanted 89$ for service without willing to provide any estimates on cost of repair, even when I said the torsion spring broke after it was replaced around 7-8 years ago. They said something along the lines of “each garage is unique and we won’t know until someone comes see it” which means you’re in the hole 89$ regardless. I tried to get them to budge on an ESTIMATE within 100$ and they couldn’t give it to me. Obviously a ripoff.
I also dealt with SEARS and they wanted 130$ to assess, then they “custom make” springs that cost 100-400$, but couldn’t give a ballpark on the price even when I told them the door size and material.
I ended up going with a local business owner who told me it would be around 150, 180, and 200 for single, double, and double with extended life torsion springs OVER THE PHONE, and that the price is an estimate with 5-10$ adjustment, so I went with him.”
https://www.firstcoastgaragedoor.com/replacing-broken-garage-door-springs/